Electric circuit breaker



Oct. 26, 1954 B. E. GETCHELL ELECTRIC CIRCUIT BREAKER 2 ShGGES ShGBt 1 Filed Aug. 7, 1951 In v nt or 5 endam n' EGetcheH y 2 Zia Attorney Oct. 26, 1954 B. E. GETCHELL ELECTRIC CIRCUIT BREAKER 2 Sheets-Sheet 2 Filed Aug. '7, 1951 I 1 INVENTOR. Bemamm E. Getchell Horney Patented Oct. 26, 1954 ELECTRIC CIRCUIT BREAKER Benjamin E. Getchell, Plainville, Conn., assignor to General Electric Company, a corporation of New York Application August 7, 1951, Serial No. 240,688

7 Claims.

The main object of this invention is to provide a circuit breaker of compact but eifective construction in which the mechanism is manually operable to open and close a circuit .and which automatically opens the circuit upon an overload in the circuit.

Another object is to provide a circuit breaker of the snap-acting type which is small and compact, but in which a comparatively great separation of contacts is possible.

Another object is to provide a circuit breaker which can successfully interrupt relatively large electric currents and especially direct currents.

Another object is to provide a circuit breaker in which the moving parts pivot on a metal frame member without the use of separate pivot pms.

Another object is to provide a circuit breaker having its handle biased to seal against the cover so as to prevent the escape of hot gases or flame.

Fig. 1 is a side view and partial section of the circuit breaker showing the parts in the normal open circuit position.

Fig. 2 is a similar view but showing the parts in the closed position.

Fig. 3 is a similar view showing the parts in the automatically tripped position.

Fig. 4 is a perspective view of the circuit breaker.

Fig. 5 is a fragmentary detail view showing the support for the finger lever.

Fig. 6 is a side view of the bridge or supporting member.

Fig. 7 is an edge view of the same.

Fig. 8 is a side view of the tripping element.

Fig. 9 is an edge view of the same.

Fig. 10 is a side view of the movable switch contact member.

Fig. 11 is an edge view of the same.

Fig, 12 is a side view of the rocker member.

Fig. 13 is an edge view of the same.

Fig. 14 is a. perspective view of the terminal and bimetal unit viewed from the outer edge.

Fig. 15 is a similar view of the unit seen from the inner face.

The mechanism is enclosed in an insulating housing consisting of a body part 8 which supports the mechanism and a removable part 9 which serves as a cover plate. The parts are held together by suitable fastening members such as screws or rivets ID, ID. A face plate ll extends across the outer edge or end of the housing and provides screw seats I l. A movable finger piece or actuating lever I2 extends outwardly from the face plate for manual operation of the circuit breaker.

Circuit terminals l4 and I5 are set into opposite ends of the body part of the housing. A stationary contact [6 is connected to the terminal l5 and a movable switch or contact member I! is connected to the thermally responsive, current responsive, or bimetal strip l8 by a flexible conductor l9, and the strip is connected to the terminal Id. The bimetal strip is carried by the arm I8a: and may be adjusted by a screw I 8' which is adjustable in arm [8. The part l8" extends laterally from the upper end of arm M which is formed integrally with the terminal M. This unit is mounted in a recess in the housing and may have projecting pins l4", l4 located in recesses in the body to assist in holding the unit in place.

A main supporting or bridge member 20 is supported at its opopsite ends in the body of the housing. This member has two sides connected by cross walls 20, 20".

The tripping member 2| also has two sides. each of which is provided with a lug 22 at one end which projects outwardly into a bearing notch. 22 in the bridge member 20 and has a cross wall 2|. The nose 23 carried by the cross wall 2| normally rests upon the tip of the bimetal strip [8. The switch member I? is hinged to the trip member 2| and for that purpose has a notch or bearing 24 at each side receiving the lug 24' which extends inwardly from the opposite end of the adjacent side wall of the trip member 2!.

The rocker 25 has opposed notched 26, 2B which provide bearings for the opposed lugs 28', 26 which project outwardly from the sides of the bridge 20. This rocker has an integral arm 2'! connected to it by a cross wall 28. A spring 30 is anchored at one end to the pin 3! on the arm 21 and is connected at H at its other end to the movable switch member I]. This spring biases the switch member I 7 against the stop 32 on the wall 20' of the bridge 28.

The operating finger piece 12 is connected to its insulating hub 33 on the rock shaft 34 supported between body 8 and cover 9. A helical spring 344a surrounds the shaft 34 and serves to bias the hub 33 upwardly into engagement with flange or socket II" on the face plate H.

As shown in Fig. 5, the helical spring 34a has its opposite ends extending respectively into cylindrical recesses 34b and 36c in the opposite inner walls of the housing parts 8 and 9. Likewise, the ends of the rock shaft 34 extend into these recesses, the rock shaft having a diameter considerably smaller than the inside diameter of the spring, with the end portions of the rock shaft in the recesses resting on the end turns of the helical spring. By reason of its transverse resiliency, the spring applies a biasing force in an upward direction, as seen in Fig. 5, to the hub thereby holding the spherical portion 33a of the hub seated in the complementary outwardly arched spherical flange. ll on the base or end plate l Ii aroundthe periphery of the aperture for the finger piece l2. It will be understood that the rock shaft serves to limit the. downward movement of the hub in the event that it is pushed downward with a force greater than the bias of the spring. ilhe transverse aperture 3M in the hub through whichthespring extends has a diameter at its middle substantially the same as the recesses and slightly greater than the outside diameter or the spring, and gradually increases in diameter from the. middle toward each end so that the middle wall of the aperture engages the spring to make effective the maximum transverse resiliency of the spring.

A bearing 35 which connects the two sides of the rocker extends into a slot 35 in the hub 33 for moving the rocker.

The spring 33 when the. arm 27. is in lower position pulls the movable switch member i! into closed circuit position as shown in Fig. 2-, and when the arm. 27: is in, upper position the spring pulls the switch member to the open circuit position as shown in Fig. 1.

When in closed circuit position, the part 28 abuts against the body of the housing at 28".

To manually open the circuit, the lever [2 is moved to the left from the position of Fig. 2 to the position of Fig. 1. This turns the rocker 25 about pivots 26 in a clockwise direction and carries the anchor end of the spring 36 above the pivot lugs 24" and throws the switch member H to the off or open circuit position. In this position, the wallZB abuts against the bridge member 20.

To close the circuit after manual opening, the lever I2 is manually moved to the right from the position of- Fig. 1 to the positionof Fig, 2 thereby turning the rocker 25 anticlockwise about its pivots 2G. This moves the arm 27 downwardly carrying the anchoredend of the spring 36' below. the, bearings M so that the spring turns the movable switch. contact it around said bearings 2 and snaps, it into closed position against the stationary contact it.

When the circuit is closed andan overload. in the circuit warps the bimetal strip l8, the nose 230i the trippingmernber it is released'and the spring 36, acting through the switch member l'i, applies pressure against the pivot bearings 2d" of the tripping member 2!, turns the. tripping member about the bearings 22'', andthrows the trip member'into the position of Fig. 3 thereby. carrying't-he switch member I? to of? position.

To reset the switch mechanism, after being. tripped to the open position of Fig. 3',.the lever W is manualy moved" to the left thereby. turning. The. wall 213.-

rocker 25 clockwise on pivots 23".. then engagesthe lower edge ofthe trip member 21. and. turns. it. clockwise. about the pivots 22 Ihis forcesthe nose 23 to. travel upwthe bimetalstrip l8- until it latches. on to the tip of the bimetal as shown in Fig. .1.

I claim:

1. In a circuit breaker, a housing; having aninsulating body. a'mejtalrace plate secured: to..=the, body, said. plate having an: openin with an; outwardly arched, peripheral flange: provided. with a seat, an actuatingfinger piece: having a.

hub with .a transverse opening therein, a transverse bearing pin for said hub extending through said hub opening and supported loosely in the body, and a helical spring on said pin pressing said hub to the seat in said fiange.

2. In a circuit breaker, a housing having an insulating body, a metal face. plate secured to the body,. said plate having. an opening with an outwardly arched flange forming a seat, an actuating finger piece having a hub with a transverse opening therein, a transverse bearing pin for said hub extending through said hub opening, and supported loosely in the body, and a helical spring of larger diameter than said pin on said pin pressing said hub to said seat within said flange.

3'. In a circuit breaker, a housing having spaced side walls and an end wall provided with an opening, switch means mounted in said housing, a manually operated lever for said switch means projecting from said opening including a hub in said housing having a transverse aperture, closure means for said opening carried by said; lever, and a helical spring extending through said transverse aperture having its ends. secured to said side walls so as to bias said lever to a position closing said opening.

4. In a circuit. breaker, a housing having spaced side walls provided with opopsite cylindrical recesses and an end wall provided with an opening, switch means mounted in said housing, a manually operated lever for said switch means projecting from said. opening including a hub in said housing having a transverse: aperture extending. between said recesses, closure means for said opening carried by said lever, and a helical spring extending through said transverse aperture havin its endsiextending into said recesses so as to bias said lever to a position closing said opening.

5'. In a. circuit breaker, a: housing having spaced walls provided with opposite cylindrical recesses and an end wall provided with an opening, switch means mounted in said housing, a manually operated lever for said switch means projecting from said openin including a hub in said housing having-a transverseaperture'extend ing between said recesses, closure means forsaid. opening carried by said lever, a helical. spring extending through said transverse aperture having its ends extending into said recesses so. as to bias'saidleverto a. position closing said opening, and a bearing pin having a diameter substantially smaller than the inside diameter. of said' spring extending; through said spring, and

" having its. ends extending ihtosaid recesses-for limiting the movement of said lever relative to said end wall.

6. In a circuit breaker, a housing having spaced walls provideclwith. opposite. cylindrical recesses andlarrend wallprovided with an opening, a spherical. flange on. said end wall. around said opening, switch means. mounted in said housing, a manually operated lever. for. said: switch. means projecting from. saidopening including a hub insaidhousinghaving, a surface? fitting into. said. flangeanda. transverse. aperture extending between-said. recesses, said" trans-- verse aperturehavin-g substantially thesame: di ameter. atitsa middle: as said recesses but grade ually increasing in diameter from.- the middle towardeach end, and-a helical. spring: extending; through said. transverse aperture having. its; ends. extending; into saidrecessesso; asto bias said; hub against said flange.

'7. In a circuit breaker, a housing having spaced walls provided with opposite cylindrical recesses and an end wall provided with an opening, a spherical flange on said end wall around said opening, switch means mounted in said housing, a manually operated lever for said switch means projecting from said opening including a hub in said housing having a spherical surface fitting into said flange and a transverse aperture extending between said recesses, said transverse aperture having substantially the same diameter at its middle as said recesses but increasing in diameter from the middle toward each end, a helical spring extending through said transverse aperture having its ends extending into said recesses so as to bias said hub against said flange, and a bearing pin having a diameter substantially smaller than the inside diameter of said spring extending through said spring said flange.

References Cited in the file of this patent UNITED STATES PATENTS Number Number Name Date Douglas May 16, 1933 Row Sept. 5, 1939 Rypinski Dec. 7, 1943 Hutt Oct. 17, 1944 Graves, Jr. Apr. 3, 1945 Freese Feb. 18, 1947 FOREIGN PATENTS Country Date France Aug. 21, 1912 Germany May 6, 1940 

